1. Field of Invention
The technical scope of the invention is that of sealing bases for munitions, notably large calibre, as well as devices to fasten them onto an ammunition case.
2. Description of Related Art
A sealing base is known notably by patent DE2303790 that comprises a steel body having a cylindrical rim onto which a rubber sealing ring is affixed.
This base is joined to a combustible case by means of a washer arranged in a groove of an axial extension of the base.
The main drawback of such a device lies in that the base can not be fastened to the case before said case has been filled with powder.
Disassembly of the base at a later date proves impossible without the disassembly of the whole projectile and removal of the powder.
A base is also known by U.S. Pat. No. 5,048,421 that is fastened by being screwed onto a threaded part of the combustible case.
However, such a solution is complicated since it requires the manufacture of a case incorporating a threaded part, this being difficult to reliably obtain for a case of a combustible material such as nitrocellulose impregnated cardboard.
Lastly, patent EP463904 describes a base that incorporates a flexible ring intended to co-operate with a groove carried on a tubular part integral with the combustible case bottom.
Such a solution has the drawback of being structurally complicated, relatively fragile and impossible to disassemble.
It is the aim of the invention to propose a sealing base fastening device that does not suffer from the drawbacks of known devices.
Thus, the device according to the invention allows a base to be fastened to a combustible case after this has been filled with powder.
The base can be easily disassembled so as to carry out inspection or powder replacement operations.
Thus, the subject of the invention is a joining device for a sealing base of an ammunition, notably for a large calibre munition having a combustible case, device in which the case carries or is fitted with a cup having a central opening, said device being characterised in that support means are fastened to the cup by first linking means, said supporting means being in the form of a rod incorporating a cylindrical support onto which a bore of the base is positioned, said base being made integral with the support means by second linking means.
Advantageously, the support means can be formed by an ignition system.
The support means can incorporate a threaded part intended to co-operate with a nut that constitutes the second linking means and is housed in a countersink arranged in the base.
The cup can be formed as part of the combustible case or else be made integral with a cylindrical wall of the case by fastening means.
According to a particular embodiment, the first linking means can comprise an intermediate part fastened at the central opening.
According to one embodiment, the intermediate part can be a ring incorporating a circular groove housing the rim of the central opening, said ring having at least two elastically deformable lips allowing the rim to be introduced into the groove.
According to another embodiment, the intermediate part can comprise a circular groove housing at least two tabs integral with the cup.
The cup can incorporate at least one side opening allowing the powder to be introduced.
The cup can incorporate at least three openings evenly spaced angularly and delimited by radial arms converging towards an axial ring-shaped collar.
A further subject of the invention is a base adapted so as to be able to be made integral with a case using such a fastening device.
The sealing base according to the invention is intended to be made integral with a combustible case using such a joining device. This base is characterised in that it incorporates a smooth axial bore intended to co-operate with a rod-like support means integral with the case.
The axial bore of the base will be enlarged into a countersink on the rear face of the base, said countersink being able to accommodate a fastening nut.